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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Algorithms and architectures for decimal transcendental function computation

Chen, Dongdong 27 January 2011
Nowadays, there are many commercial demands for decimal floating-point (DFP) arithmetic operations such as financial analysis, tax calculation, currency conversion, Internet based applications, and e-commerce. This trend gives rise to further development on DFP arithmetic units which can perform accurate computations with exact decimal operands. Due to the significance of DFP arithmetic, the IEEE 754-2008 standard for floating-point arithmetic includes it in its specifications. The basic decimal arithmetic unit, such as decimal adder, subtracter, multiplier, divider or square-root unit, as a main part of a decimal microprocessor, is attracting more and more researchers' attentions. Recently, the decimal-encoded formats and DFP arithmetic units have been implemented in IBM's system z900, POWER6, and z10 microprocessors.<p> Increasing chip densities and transistor count provide more room for designers to add more essential functions on application domains into upcoming microprocessors. Decimal transcendental functions, such as DFP logarithm, antilogarithm, exponential, reciprocal and trigonometric, etc, as useful arithmetic operations in many areas of science and engineering, has been specified as the recommended arithmetic in the IEEE 754-2008 standard. Thus, virtually all the computing systems that are compliant with the IEEE 754-2008 standard could include a DFP mathematical library providing transcendental function computation. Based on the development of basic decimal arithmetic units, more complex DFP transcendental arithmetic will be the next building blocks in microprocessors.<p> In this dissertation, we researched and developed several new decimal algorithms and architectures for the DFP transcendental function computation. These designs are composed of several different methods: 1) the decimal transcendental function computation based on the table-based first-order polynomial approximation method; 2) DFP logarithmic and antilogarithmic converters based on the decimal digit-recurrence algorithm with selection by rounding; 3) a decimal reciprocal unit using the efficient table look-up based on Newton-Raphson iterations; and 4) a first radix-100 division unit based on the non-restoring algorithm with pre-scaling method. Most decimal algorithms and architectures for the DFP transcendental function computation developed in this dissertation have been the first attempt to analyze and implement the DFP transcendental arithmetic in order to achieve faithful results of DFP operands, specified in IEEE 754-2008.<p> To help researchers evaluate the hardware performance of DFP transcendental arithmetic units, the proposed architectures based on the different methods are modeled, verified and synthesized using FPGAs or with CMOS standard cells libraries in ASIC. Some of implementation results are compared with those of the binary radix-16 logarithmic and exponential converters; recent developed high performance decimal CORDIC based architecture; and Intel's DFP transcendental function computation software library. The comparison results show that the proposed architectures have significant speed-up in contrast to the above designs in terms of the latency. The algorithms and architectures developed in this dissertation provide a useful starting point for future hardware-oriented DFP transcendental function computation researches.
42

Lågoffsetkomparator / Lowoffsetcomparator

Fransson, Daniel January 2002 (has links)
Detecting small signals with a comparator demands that the total voltage offset is lower than the actual signal. The total offset includes the voltage offset in the comparator and the voltage offset that is created by the offset currents that flows thru the load at the comparators input. The goal with this comparator that has been developed has been that it will have a total voltage offset at maximum 500 uV. The comparator does not need to be extremely fast or does not need to operate in a big frequency area. To have all the flexibility that is needed a full custom technique is used. When the mismatch is most unfavourable the total offset is 209.24 uV which is within the goal. / För att kunna detektera små signalnivåer med en komparator krävs att den har en lägre total spänningsoffset än den signalnivå den skall detektera. I den totala offseten ingår dels den rena spänningsoffseten i komparatorn och dels den spänningsoffset som kommer att skapas när offsetströmmar på komparatorns ingångar går igenom den last som finns på ingången. Målet med den komparator som utvecklats har varit att den skall ha en total spänningsoffset på maximalt 500 uV. Inga direkta krav såsom att den skall vara snabb och att den skall kunna arbeta inom ett stort frekvensområde finns. För att få den flexibilitet som behövs är komparatorn konstruerad i en så kallad full custom teknik. När missanpassningen är som mest ogynnsam hamnar den totala spänningsoffseten på 209.24 uV vilket ligger inom målet med god marginal.
43

Algorithms and architectures for decimal transcendental function computation

Chen, Dongdong 27 January 2011 (has links)
Nowadays, there are many commercial demands for decimal floating-point (DFP) arithmetic operations such as financial analysis, tax calculation, currency conversion, Internet based applications, and e-commerce. This trend gives rise to further development on DFP arithmetic units which can perform accurate computations with exact decimal operands. Due to the significance of DFP arithmetic, the IEEE 754-2008 standard for floating-point arithmetic includes it in its specifications. The basic decimal arithmetic unit, such as decimal adder, subtracter, multiplier, divider or square-root unit, as a main part of a decimal microprocessor, is attracting more and more researchers' attentions. Recently, the decimal-encoded formats and DFP arithmetic units have been implemented in IBM's system z900, POWER6, and z10 microprocessors.<p> Increasing chip densities and transistor count provide more room for designers to add more essential functions on application domains into upcoming microprocessors. Decimal transcendental functions, such as DFP logarithm, antilogarithm, exponential, reciprocal and trigonometric, etc, as useful arithmetic operations in many areas of science and engineering, has been specified as the recommended arithmetic in the IEEE 754-2008 standard. Thus, virtually all the computing systems that are compliant with the IEEE 754-2008 standard could include a DFP mathematical library providing transcendental function computation. Based on the development of basic decimal arithmetic units, more complex DFP transcendental arithmetic will be the next building blocks in microprocessors.<p> In this dissertation, we researched and developed several new decimal algorithms and architectures for the DFP transcendental function computation. These designs are composed of several different methods: 1) the decimal transcendental function computation based on the table-based first-order polynomial approximation method; 2) DFP logarithmic and antilogarithmic converters based on the decimal digit-recurrence algorithm with selection by rounding; 3) a decimal reciprocal unit using the efficient table look-up based on Newton-Raphson iterations; and 4) a first radix-100 division unit based on the non-restoring algorithm with pre-scaling method. Most decimal algorithms and architectures for the DFP transcendental function computation developed in this dissertation have been the first attempt to analyze and implement the DFP transcendental arithmetic in order to achieve faithful results of DFP operands, specified in IEEE 754-2008.<p> To help researchers evaluate the hardware performance of DFP transcendental arithmetic units, the proposed architectures based on the different methods are modeled, verified and synthesized using FPGAs or with CMOS standard cells libraries in ASIC. Some of implementation results are compared with those of the binary radix-16 logarithmic and exponential converters; recent developed high performance decimal CORDIC based architecture; and Intel's DFP transcendental function computation software library. The comparison results show that the proposed architectures have significant speed-up in contrast to the above designs in terms of the latency. The algorithms and architectures developed in this dissertation provide a useful starting point for future hardware-oriented DFP transcendental function computation researches.
44

High Level Model of IEEE 802.15.3c Standard and Implementation of a Suitable FFT on ASIC

Ahmed, Tanvir January 2011 (has links)
A high level model of HSIPHY mode of IEEE 802.15.3c standard has been constructedin Matlab to optimize the wordlength to achieve a specific bit error rate (BER) depending on the application, and later an FFT has been implemented for different wordlengths depending on the applications. The hardware cost and power is proportional to wordlength. However, the main objective of this thesis has been to implement a low power, low area cost FFT for this standard. For that the whole system has been modeled in Matlab and the signal to noise ratio (SNR) and wordlength of the system have been studied to achieve an acceptable BER. Later an FFT has been implemented on 65nm ASIC for a wordlength of 8, 12 and 16 bits. For the implementation, a Radix-8 algorithm with eight parallel samples has been adopted. That reduce the area and the power consumption significantly compared to other algorithms and architectures. Moreover, a simple control has been used for this implementation. Voltage scaling has been done to reduce thepower. The EDA synthesis result shows that for 16bit wordlength, the FFT has 2.64 GS/s throughput, it takes 1.439 mm2 area on the chip and consume 61.51mW power.
45

Simplifying the Creation of Multi-core Processors: An Interconnection Architecture and Tool Framework

Grossman, Samuel Robert January 2012 (has links)
The contribution of this thesis is two-fold: an on-chip interconnection architecture designed specifically for multi-core processors and a tool framework that simplifies the process of designing a multi-core processor. Both contributions primarily target ASIC fabrication, though prototyping on an FPGA is also supported. SG-Multi, the on-chip interconnection architecture, distinguishes itself from other interconnection architectures by emphasizing universal adaptability; that is, a primary design goal is to ensure compatibility with industry-supplied cores originally intended for other architectures. This goal is achieved through the use of bus adapters and without introducing clock cycle latency. SG-Multi is a multi-bus architecture that uses slave-side arbitration and supports multiple simultaneous transactions between independent devices. All transactions are pipelined in two stages, an address phase and a data phase, and for improved performance slave devices must signal their status for a given clock cycle at the beginning of that cycle. SG-Multi Designer, the tool framework which builds systems that use SG-Multi, provides a higher level of abstraction compared to other competing system-building solutions; the set of components with which a designer must be concerned is much more limited, and low-level details such as hardware interface compatibility are removed from active consideration. Experimental results demonstrate that the hardware cost of using SG-Multi is reasonable compared to using a processor's native bus architecture, although the current implementation of arbitration is identifiable as an area for future improvement. It is also shown that SG-Multi is scalable; the reference systems grow linearly with respect to the number of cores when tested for ASIC fabrication and slightly sublinearly when tested for FPGA prototyping, and the maximum achievable clock frequency remains almost constant as the number of cores grows beyond four. Because the reference systems tested are an accurate reflection of the types of systems SG-Multi Designer produces, it is concluded that the abstraction model used by SG-Multi Designer does not over-simplify the design process in a way that causes excessive performance degradation or increased hardware resource consumption.
46

Design and evaluation of an integrated variable gain, low noise amplifier for medical application

Li, Chun-Yi 22 August 2011 (has links)
Acquisition of bio-signals is an important feature in advanced medical applications. In order to record bio-signals such as electrocardiogram (ECG) or electromyogram (EMG), a switched-capacitor amplifier with variable linear gain and low noise front-end is discussed in this thesis. The circuit is designed and implemented as an Application-Specific Integrated Circuit (ASIC). This ASIC consists of transconductance stage with custom-designed lateral bipolar transistors in the input stage, switched-capacitor integrating stage, sample-and-hold circuit and buffer output stage. Lateral bipolar transistors were chosen with the intention of reducing flicker noise compared to using MOS input devices. Using a switched-capacitor (SC) stage the gain is adjustable to accommodate input signals of different amplitude making it useful for the recording of different biomedical signals. Adjustable gain is achieved by varying the clock phase delay between two digital control signals which were generated by a microcontroller. Also, small size and low supply voltage operation (¡Ó0.9 V) are achieved. Therefore, this ASIC may be used in wearable or even with implantable medical applications. Measured results for test chips realized in TSMC 0.35 £gm CMOS technology are reported confirming the correct operation of the circuit.
47

Lågoffsetkomparator / Lowoffsetcomparator

Fransson, Daniel January 2002 (has links)
<p>Detecting small signals with a comparator demands that the total voltage offset is lower than the actual signal. The total offset includes the voltage offset in the comparator and the voltage offset that is created by the offset currents that flows thru the load at the comparators input. The goal with this comparator that has been developed has been that it will have a total voltage offset at maximum 500 uV. The comparator does not need to be extremely fast or does not need to operate in a big frequency area. To have all the flexibility that is needed a full custom technique is used. When the mismatch is most unfavourable the total offset is 209.24 uV which is within the goal.</p> / <p>För att kunna detektera små signalnivåer med en komparator krävs att den har en lägre total spänningsoffset än den signalnivå den skall detektera. I den totala offseten ingår dels den rena spänningsoffseten i komparatorn och dels den spänningsoffset som kommer att skapas när offsetströmmar på komparatorns ingångar går igenom den last som finns på ingången. Målet med den komparator som utvecklats har varit att den skall ha en total spänningsoffset på maximalt 500 uV. Inga direkta krav såsom att den skall vara snabb och att den skall kunna arbeta inom ett stort frekvensområde finns. För att få den flexibilitet som behövs är komparatorn konstruerad i en så kallad full custom teknik. När missanpassningen är som mest ogynnsam hamnar den totala spänningsoffseten på 209.24 uV vilket ligger inom målet med god marginal.</p>
48

Realisierung eines Verilog/VHDL Codegenerators fuer graphisch erfasste Finite State Machines

Roy, Diana 24 March 1997 (has links) (PDF)
Es wurden verschieden Kodierungsarten fuer FSMs untersucht, schwerpunktmaessig Gray Code und andere Arten der hazardfreien Kodierung. Ein spezieller Kodierungsalgorithmus zur hazardfreien Kodierung wurde entwickelt und in eine Entwurfsumgebung implementiert. Ein weitere Schwerpunkt der Arbeit sind Codegeneratoren, die eine Verhaltensbeschreibung der FSM in Verilog oder in VHDL erzeugen.
49

Investigating Meningeal Ion Channels As New Molecular Targets For Migraine

Wei, Xiaomei January 2014 (has links)
This dissertation will present the four manuscripts I published or am ready to publish on the study of the pathophysiology of migraine headache. The first chapter will discuss the background of the current understanding of migraine pathophysiology. Chapter 2 is focused on studying how Transient receptor potential vanilloid 4 (TRPV4) might play a role in migraine headache. Chapter 3 is the study of a novel cell type: dural fibroblasts might also play an active role in migraine headache. Chapter 4 is discussing Norepinephrine's role in headache pathophysiology. Chapter 5 is studying the combined effect of Acid and ATP in the pathophysiology of migraine headache. The dissertation will end in a conclusion in Chapter 6.
50

Debug Interface for 56000 DSP

Nilsson, Andreas January 2007 (has links)
The scope for this thesis was to design a debug interface for a DSP (digital signal processor). The DSP is a research version of a Motorola 56000 that is designed for a project on asynchronous processor and for use in education. The DSP and debug interface are controlled via a standard PC with RS232 interface equipped with Linux operation system. In the project 4 blocks has been designed: The first block can set the DSP core in debug mode or run mode. The second block sends a debug instruction to the DSP core, these debug instructions were prerequisite to the project. The third block enable read and write connection to the memory buses between the DSP core and the three memory blocks. The forth block can override the control signals to the memories from the DSP core. The project also uses an UART for interpreting and sending control signals and data between the different blocks and the computer. A text terminal program for Linux has also been programmed for handling the PC side communication. The hardware has been constructed and tested together with a dummy DSP core and dummy memories, but it has not been tested together with the live DSP core. The Linux program has been tested the same way and seems to do what it's supposed to, though it leaves a lot work to be easy to handle.

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